This Article takes an In-depth look at Automated Guided Vehicles
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In 1954, when Arthur "Mac" Barrett, of Barrett Electronics Corporation, unveiled the first AGV, he named it Guide-o-Matic and described it as a driverless vehicle. Guide-O-Matic was a towing machine that followed a signal given from a wire in the ceiling, which was later replaced by a wire buried in the floor. It had the simple function of pulling trailers in a warehouse.
Arthur Barrett spent his life exploring and investigating different ways of using automation to open doors, move materials, and develop other work saving devices. His radio controlled industrial vehicles were called Radox, which allowed operators to program it to pick up pallets, tow vehicles, or index a pallet truck.
The advancements of Barrett inspired engineers and designers to develop the modern systems of AGVs that use cameras, lasers, electrically charged tape, and other means to maneuver automated vehicles in various environments. The discovery of automatic guided vehicles has revolutionized raw and finished material transport.
AGVs are guided computerized vehicles that use computer software to determine their positioning, movement, and location. Powered by a battery or electric motor, they are able to complete manufacturing, warehousing, loading, and other operations without human interference. Self-powered AGVs can do load transfers, move and stack pallets, complete assemblies, and tow heavy loads, functions previously performed by people. They have improved production efficiency, removed humans from unsafe and potentially dangerous conditions and overcome possible human errors.
Though the term AGV, or automatic guided vehicle, may seem to be self defining, in actuality, there are multiple ways that AGVs receive their instructions and programming, which include wires implanted in the floor, cameras, radio waves, lasers, or other forms of technology.
AGVs began as a method of towing trailers to speed up production. At the time, they were considered nice conveniences that saved time. During the latter part of the twentieth century, designers explored other ways to use the technology to improve factory conditions, which has led to a wide array of capabilities, uses, and functions for AGV technology.
Three types of AGVs are towing, fork trucks, and heavy load carriers. Each is designed to perform repetitive actions such as delivering raw materials, keep loads stable, and complete simple tasks. Unlike human workers, AGVs operate continuously only needing to stop to be recharged or repaired.
Towing AGVs, also known as tugs or warehouse tuggers, are designed to pull loads weighing several tons, significantly reducing the risks associated with using large, heavy equipment. These AGVs are capable of moving loads ranging from 10,000 to 50,000 pounds. Heavy-duty towing AGVs are particularly useful for transporting sub-assemblies, machine components, equipment, and other materials that are too heavy or unsafe for manual handling.
Fork AGVs are mechanized forklifts that can retrieve stock, place materials, and move and stack pallets. They supply automated machines and take finished products to storage or place them for shipment. Forklift AGVs can prove to be economical and cost savings since they replace lift trucks and Hi-Lo operators that require licensing and training. Heavy-duty forklift AGVs can move large paper rolls, steel coils, engines, and vehicles over any distance depending on their programming
Though towing and fork AGVs are capable of handling large loads, certain industries such as aviation, large construction vehicle manufacturers, and shipbuilders require AGVs able to handle huge loads of up to 250,000 pounds. For these processes, AGV producers have created machines with large bases, solid wheels, and wide platforms. In many cases, this form of AGV has to be custom designed to exactly fit the requirements of the customer‘s industry.
Unit load AGVs have one specialized function, which is transporting totes, pallets, goods, and racks that are too heavy to be moved by other means. They are designed to move goods and heavy materials in a warehouse or storage facility. Unlike fork and towing AGV‘s, unit load, or unit load decks, are flat tables that can carry one or several individual units to and from conveyors, stands, automated storage, and various types of retrieval systems. Very similar to a flatbed, they usually move along one path in two directions, repetitively, and without variations.
Light-duty AGVs are commonly used outside of production facilities, such as in hospitals, offices, or commercial locations. These AGVs are designed to move very small loads, typically under 500 pounds. Small AGVs are particularly valuable in environments where cleanliness is crucial and human presence might introduce contamination. For example, in hospitals, they are often used to deliver patient charts and daily medications.
AGV robots are automatic guided vehicles equipped with robotic limbs. AGV robots are more adept at picking up and moving items than regular AGVS, which are must less dexterous. In short, they combine the intuitiveness of a human and their ability to adjust to their surroundings, and combine them with the brute force of a lifting machine like a palletizer.
AGV robots offer numerous benefits to their users. They enable manufacturers to save time and money by performing tasks more efficiently than humans. For example, during auto parts assembly, AGV robots can assemble large components faster and can even execute tooling switches autonomously. Additionally, AGV robots have no learning curve; once programmed, they perform their duties flawlessly. Their precise programming reduces human error and enhances accuracy. By handling potentially hazardous tasks, they keep personnel out of harm’s way. In loading and unloading applications, AGV robots provide greater mobility and strength, eliminating the need for human involvement in high-stress or high-risk situations. Another advantage of AGV robots is their ease of setup compared to traditional AGVs, as they require fewer physical markers and guides.
The term "AGV systems" refers to automated, or automatic, guided vehicles. AGV systems run on industrial batteries or electricity to perform movement solutions within warehouses and facilities. Solutions include material handling, transportation, assembly, delivery and storage; these solutions have applications within most industries, including: greenhouse, general manufacturing, plastics and metal, newspaper and mail, automotive, aerospace, food and beverage processing and packaging.
To ensure smooth operations, AGV systems typically require monitoring. This is particularly crucial in large factories or warehouses, and especially when multiple AGV systems are in use. In such cases, traffic operating systems and controllers become essential components. These systems generally include locator panels, CRT displays, and a central logging and report center. With this technology, staff can effectively monitor and track the location and movement of AGV systems within the facility, assess their efficiency, and prevent collisions and traffic congestion.
Automated guided vehicles, also known as automatic guided vehicles or AGVs, are computer operated, self-powered transportation equipment used for applications within the material handling and moving industry. Though they were originally designed to serve only industrial market transportation and lifting, their use is now more widespread. Fields within which they are now used also include: general manufacturing, food and beverage processing, automotive, aerospace, packaging, greenhouse/industrial horticulture, metals and plastics and mail and newspaper.
These systems operate using either fixed guidance or free-range systems. Fixed guidance relies on magnetic tape, colored paint, or embedded wires to guide vehicles, which respond to antennae, signal emissions, and frequencies along simple paths. While fixed guidance systems are reliable and effective, they are also inflexible, limiting the capabilities of their AGVs, and may not be well-suited to certain environments and applications. Fortunately, most modern automated guided vehicles (AGVs) are not restricted by fixed guidance systems. Instead, contemporary AGV systems typically utilize free-range systems, which are computer-controlled with onboard microprocessors and supervisory control systems.
Guided vehicles are computer-controlled transportation units that perform applications without any sort of human direction or control. They are used for material handling and transportation applications and can be designed for sorting, storage, delivery or product assembly use. Guided vehicles, or automatic guided vehicles, reduce labor costs in manufacturing processes by providing high volumes of repetitive and tedious movements and actions with around the clock capabilities.
Vehicles can be equipped with an infrared detection system or a bumper system, which helps to minimize the potential damage from collisions. Free-range AGV systems, controlled by computer software and equipped with internal navigation capabilities, can adjust a vehicle's route according to traffic flow and potential obstructions, making the factory floor a safer place to work.
Laser guided vehicles are capable of moving independently and managing and improving logistical operations. They navigate using a laser positioning system with an on board computer for correct speed and location. The laser scans three reflectors to calculate its position and angles, a process that occurs eight times per second. LGV vehicles have 2 dimensional laser emitters that emit a continuous beam of modulated laser light in a 360o pattern. The beam that comes back from the reflector is used to determine the X and Y coordinates of the reflector and the LGV.
Like other positioning systems, three points are used to determine the exact location of the LGV. The system boasts an accuracy of ±10 mm (±0.394 inches) when using four reflectors within an 8-meter (26-foot) radius. To achieve specific positioning, asymmetrical placement of reflectors or targets is necessary, with calculations made 30 or 40 times per second. This placement allows the LGV to automatically switch between automatic and manual modes as it travels along its route. Complex routes can be divided into fixed areas or layers, with up to 200 layers used to layout a track or route.
There are two main types of reflectors used for LGVs: flat and cylindrical. Flat reflectors, often made from reflective tape, are the least expensive and can be easily installed or repositioned thanks to their adhesive backing. Cylindrical reflectors, on the other hand, require precise calculation of a fixed center point for installation, making them more difficult to install and fix, as well as more susceptible to damage. Despite these challenges, the primary advantage of using reflector systems is the accurate positioning they provide for LGVs. Additionally, LGVs can operate at speeds of 2 meters per second (6 feet per second), enhancing efficiency and performance.
There are four main types of laser-guided vehicles: high reach lift LGVs, fork LGVs, conveyor-bed LGVs, and reel LGVs. High reach lift LGVs, capable of carrying up to 1200 kg (2645 lbs), are used for pallet handling and stacking pallets up to 9 meters (29 feet) high. Forklift LGVs are designed for handling one to four pallets and delivering stable loads. Conveyor bed LGVs can transport multiple products simultaneously and are utilized in high-speed sortation, material flow and transport, distribution, and raw material handling.
Self-guided vehicles (SGVs) are computer-controlled transportation units designed to operate autonomously, without any human intervention or control. These vehicles are increasingly replacing forklifts, conveyor systems, and manual push-carts due to their ability to handle high volumes of movement, particularly in repetitive and continuous processes. Industries such as aerospace, automotive assembly, food and beverage processing, mail services, assembly lines, newspapers, pharmaceuticals, plastic manufacturing, and storage facilities rely on AGVs for tasks like sorting, delivering, transporting, and assembling operations.
Self-guided vehicles vary widely in construction and shape depending on their specific application. They may feature towing mechanisms, spaces for unit or pallet loading, forklifts, compartments for light loads, or components such as robotic arms needed for assembly lines. These variations ensure that SGVs can be tailored to meet diverse operational requirements efficiently.
Light load vehicles can be used for small parts distribution and assembly, while much larger vehicles such as towing vehicles can be used for moving heavy and cumbersome loads. Other self-guided vehicles are designed for use in specific environments such as those used in clean room processes and operations. These electric battery powered vehicles are useful in indoor applications where no sudden or essential decisions are made that cannot be done by automated machinery.
Self propelled vehicles, also known as automatic guided vehicles, are able to perform applications without any sort of human direction or control, thus allowing operational processes and tasks to be achieved more efficiently and more often. AGV systems provide high volumes of repetitive movement and can be designed with the capacity for far greater loads and weights than manual labor provides. They also reduce the factor of human negligence in the movement of vehicles and loads, thereby reducing the risk of bumping, crashes and collisions on the manufacturing floor. Self propelled vehicles are typically powered by industrial strength batteries or electricity. Required power capacity will depend on the intended application and load of the vehicle, and can be adjusted to fit custom specifications. Automated guided vehicles were originally designed for use in industrial activities, but have become popular alternatives to manual cart transports, conveyors and forklift trucks in many types of applications.
Towing vehicles, also known as tuggers, are unmanned, computer controlled transport vehicles that are capable of pulling the heavy loads of one or more unpowered, wheeled trolleys. They are one of the most effective types of automatic guided vehicles. Loaded carts, trailers, or trolleys are attached to the AGV and pulled to a location for loading or unloading.
Automated Guided Vehicles (AGVs) use various guidance systems, with fixed and free-range systems being the most prevalent. Fixed path systems employ sensors embedded in the floor, tape, navigation wires, laser target sensors, or ultraviolet light to detect obstacles in the AGV's path. In contrast, free-range AGVs are equipped with onboard computers programmed with a facility map. These AGVs initially use the map to navigate and, much like robots, can operate autonomously.
An AGV's load capacity depends on its size and motor specifications. Different types of AGVs come with various motors and towing capabilities. A typical AGV can tow up to 1.5 tons (3,300 pounds or 1,496 kg), while larger models can handle up to 20 tons (18,143 kg). Magnetic-guided AGVs travel at speeds of 195 ft per minute (60 m per minute), whereas those with laser navigation systems can reach speeds of 780 ft per minute (240 m per minute).
For towing vehicles, 24V and 48V GEL batteries are the most commonly used. Smaller, lighter vehicles typically utilize 24V batteries, while larger, more robust vehicles use 48V batteries. Some specially designed towing vehicles feature multiple batteries to extend operational time between charges. A fully charged towing vehicle generally operates for up to 10 hours, whereas those with multiple batteries can run for up to 24 hours before needing a recharge.
Towing vehicles are often paired with other AGVs, such as transfer cars or material handling robots, to efficiently move large numbers of carts without manual effort. They enhance safety in the workplace and boost productivity. Towing vehicles find applications in various industries, including metal processing, warehousing, automotive, food processing, agriculture, aerospace, construction, communications, and the military.
Autonomous mobile robots are designed to perform tasks and complete applications without human intervention. They are programmed to gather environmental information, enabling them to avoid obstacles and adapt to their surroundings independently.
Basic autonomous mobile robots use infrared or ultrasound sensors for navigation within facilities, eliminating the need for human control. More advanced robots utilize stereo vision, depth-sensing cameras, and sophisticated location software to classify and navigate around obstacles in real time.
These robots relieve humans from repetitive tasks such as delivering reports, distributing mail, and picking up items. Unlike factory robots, which are stationary, autonomous mobile robots are mobile and equipped with decision-making capabilities, allowing them to traverse their environment freely without human oversight.
The four primary types of autonomous mobile robots are collaboration robots, inventory transportation robots, scalable storage picking robots, and automatically guided vehicles (AGVs).
An AGV forklift, also known as an Automated Lift Truck (ALT), is a computer-controlled, self-driving forklift capable of performing tasks such as lifting loads, moving equipment, and executing all functions of a manned forklift. Programmed with a set of instructions or commands, AGV forklifts eliminate the need for a human operator while maintaining the same operational parameters as their manually driven counterparts.
Like traditional forklifts, AGV forklifts are designed for horizontal and vertical movement and lifting. They can stack, remove pallets from assembly lines, and load trucks. Integrated into a complex control system with various robotic and computerized devices, AGV forklifts receive their task instructions from a central control system. These instructions, coded to perform specific tasks like relocating items, guide the forklift's operations.
Communication between the AGV forklift and the control system is managed via Wi-Fi. Upon receiving commands, the AGV forklift uses its navigation system to move to the specified location, avoiding obstacles, walls, and people through its sensors. This navigation system resembles that of electric vehicles, which alert drivers if they stray from their lane or approach other vehicles too closely. After completing its task, the AGV forklift sends a notification back to the central control system.
The cost of an AGV forklift depends on its load capacity, lifting height, and battery type, ranging from approximately $50,000 to nearly $200,000. As the price increases, so do the features and capabilities. Small pallet mover AGVs typically cost between $50,000 and $70,000, while advanced AGV forklifts that can retrieve items from high storage racks can approach $200,000 but offer exceptionally robust capabilities.
Types of AGV forklifts include pallet movers or pallet jacks, pallet stackers, counterbalanced fork trucks, straddle vehicles, very narrow aisle (VNA) AGVs, and reach trucks. Counterbalanced fork trucks are designed for the highest load capacities with average reach, while VNAs, although having lower load capacities, are ideal for use in narrow aisles with high racking systems.
Heavy burden AGVs, or heavy AGVs, are specialized automated guided vehicles designed to handle exceptionally heavy loads, such as printing press paper rolls, steel coils, production engines, and large vehicles. These AGVs are tailored to meet the demands of unique applications with specialized lifting and load capacities while maintaining maneuverability comparable to smaller AGVs. They undergo rigorous testing and harsh operational cycles during assembly to ensure their effectiveness and safety.
The structural design of heavy AGVs enables them to lift up to 165 tons (150 metric tons) and transport heavy tools. They are equipped with communication systems similar to those used in smaller AGVs, which facilitate coordination and precise movement. Heavy AGVs feature multiple servo lift arbors, suspended wheel assemblies, and caster assemblies. Despite their large size and the weight of their loads, they offer precision control with a location error factor of ±0.06 inch (±1.5 mm) at pick locations. Due to their size and load, heavy AGVs operate at slower speeds compared to smaller AGVs.
Typical types of heavy AGVs include:
Red Viking, based in Michigan, manufactures a diverse range of industrial production equipment, including heavy AGVs for truck and equipment assembly. Their products are engineered, designed, and built to address the specific needs of industrial assemblies. Red Viking offers solutions in manufacturing, testing, operational intelligence, and assembly, particularly for heavy equipment. Their AGV solutions encompass tugger AGVs, conveyor AGVs, heavy AGVs, and part delivery AGVs.
DEMATIC, a rapidly growing manufacturer of material handling AGVs and AGV and AMR software, was founded in Germany over two hundred years ago as Mechanische Werkstätten Harkort & Co. They produce AGVs designed for automatic storage, retrieval, and picking in warehouses. With their proprietary software, DEMATIC AGVs enhance warehouse management systems by ensuring consistent and efficient material flow. Their product lineup includes staddle AGVs, high reach AGVs, narrow aisle AGVs, and tugger AGVs. Additionally, DEMATIC collaborates with customers to develop custom solutions for unique material handling challenges.
IDC, a Michigan-based company, specializes in automated guided carts, tonnage monitors, and industrial control systems. Their primary focus is on various types of controllers and PLCs. IDC’s carts utilize magnetic tape for guidance and support operations ranging from simple delivery routes to multiple destination deliveries. Their AGC vehicles can be equipped with automatic charging stations and PLC controllers that interface seamlessly with a company’s information system.
Daifuku manufactures AGVs for automated retrieval and storage (AS/RS) operations in factories and distribution centers. Their AGVs use a wireless communication laser-guided system, enabling them to autonomously navigate through facilities. Additionally, Daifuku provides wired, inertial, and magnetic tape options in various sizes to handle a wide range of transport loads. Their AGVs are designed to replace traditional conveyor lines, forklifts, and handcarts, enhancing efficiency and automation in material handling.
Transbotics designs, engineers, and installs heavy load AGVs, forklift AGVs, and tugger AGVs, offering specialized custom solutions for unique and unusual applications. Their AGVs are equipped with lithium batteries, blue LED directional spotlights, laser bumpers, and touch screen panels for vehicle assessment and status monitoring. Transbotics' forklift AGVs have a load capacity of 1800 kg (2 tons) and feature a counterweight for handling heavy payloads. Their tugger AGVs can tow up to 29,000 kg (32 tons), making them suitable for diverse industrial and warehousing needs.
Each AGV manufacturer customizes their vehicle configurations to ensure optimal performance, efficiency, and productivity. Engineers continually refine various components to set their equipment apart from competitors and offer a unique customer experience. Despite differences in assembly and brand-specific configurations, all AGVs require the same core components, which may be arranged differently depending on the manufacturer.
The fundamental components of AGVs encompass safety systems, navigation systems, control systems, motion systems, power systems, user interface systems, and connectivity systems. Every AGV includes these systems, although their orientations and placements can vary by brand.
The purpose of AGVs is to alleviate personnel of mundane and repetitive tasks to increase and improve productivity. When an AGV is activated to complete a task or routinely moves about a facility, it must perform in such a way that prevents damage to people, objects, and its environment. AGV safety features, such as lasers, help to detect and avoid obstructions.
Safety systems in AGVs rely on sensors such as LiDAR, cameras, and ultrasonic sensors to detect, avoid, and navigate around potential hazards. When an AGV encounters an obstacle, it either waits for it to be cleared or maneuvers around it. A crucial component of the safety system is the drive monitor, which integrates all safety scanners into a unified solution. The travel guide is monitored through the safety encoder and the drive monitor, with the steering position being continuously compared and assessed against other parameters.
Similar to electric vehicles (EVs), AGVs are equipped with warning fields that indicate their proximity to obstructions. If the safety controller detects an obstruction within one of these warning fields, it instructs the control system to slow down. The drive monitor then detects this speed change and adjusts the warning and protective fields accordingly. If a load is being placed, direction is changed, or the AGV is moving along a path, a breach of the warning field triggers an immediate reduction in speed. In cases where the closest warning field, marked by the red zone, is breached, the AGV will stop instantly.
Even with the safety system's prompt responses, there may be instances where an AGV needs to be stopped more quickly than the system can manage. In such cases, an emergency stop button is available for manual activation to prevent major threats and protect both the AGV and surrounding individuals.
The main system of an AGV is its guidance system that helps it navigate through its tasks and positions it correctly. There are several forms of navigation systems with new ones being introduced that include innovations and new technologies to improve accuracy and performance. Regardless of the type of system, the navigation system localizes and navigates an AGV through its surroundings.
None of the systems on an AGV operates independently; they are all interconnected to ensure optimal performance. The navigation system, for example, communicates with both the safety system and the vehicle control system. A fundamental component of the navigation system is the array of sensors positioned on the exterior of the AGV.
There are two primary types of navigation systems used in AGVs: fixed path and free range. Fixed path systems are guided by physical markers such as wires, tape, or wall sensors, creating a defined path that minimizes interference from vehicles or people. In contrast, free range systems operate based on a pre-programmed path and do not rely on external guidance devices. These systems are designed to make real-time adjustments to avoid collisions and hazards, providing greater flexibility and ease of installation without significant alterations to the work environment.
The types of sensors used in AGVs include:
AGV’s vehicle control system regulates its speed and actuators such as motors, brakes, and steering. The adjustment of speed is necessary when going around curves, passing through controlled areas, and avoiding contact with other vehicles and people. The AGV vehicle control system is responsible for coordinating the vehicle's motion such that it performs accurately with precision.
An AGV battery supplies the necessary power and energy for the operation of an AGV, storing and delivering energy to other systems. The effectiveness of a battery is closely tied to its charging system, as the battery and charger work together to ensure optimal performance. The three main types of charging systems are opportunity, battery swap, and automatic.
Opportunity charging involves recharging the AGV battery during breaks or idle times rather than parking it in a dedicated charging station. This method allows the AGV to be continuously operational, with charging occurring at various times throughout the workday, such as during breaks, shift changes, or pauses in activities. This method eliminates the need for battery swapping and ensures ongoing use.
Battery swapping is the process of replacing a depleted battery with a fully charged one. This can be done manually by an operator or automatically with a machine designed for the task. Automated systems facilitate this process by handling the removal and replacement of batteries without human intervention.
The types of AGV batteries include GEL batteries, AGM lead batteries, lithium batteries, and flooded lead acid batteries.
GEL Batteries - GEL batteries use a sulfuric acid and fumed silica mixture to create a gel-like substance that holds the lead plates and active materials in place. This gel combines the electrolyte and plates into a single unit. During discharge, oxygen from the positive plate is absorbed by the negative plate, which then produces water to maintain the battery's water content. GEL batteries are maintenance-free, spill and leak-proof but are not suited for opportunity charging.
Absorbent Glass Mat (AGM) Batteries - AGM batteries feature an electrolyte held in place by fiberglass mat separators, which act like a sponge. Their thin plates allow for more positive plates and greater energy density. AGM batteries have slow electrolyte absorption, which extends their lifespan.
Both GEL and AGM batteries are sealed lead acid (SLA) and valve regulated lead acid (VRLA) types with similar features. They are non-spill, maintenance-free, have deep cycle capabilities, low discharge rates, no gas emissions, and require no special handling. GEL batteries typically last 12 to 16 hours before recharging, while AGM batteries can last up to 40 hours.
Lithium Batteries - Lithium batteries offer 5000 recharge cycles, significantly more than the 1500 to 1800 cycles of GEL and AGM batteries. Lithium ions move between the cathode and anode internally, creating electrical current. During discharge, lithium ions from the anode power the AGV, and during charging, they are transferred back to the cathode.
Flooded Lead Acid Batteries - Flooded lead acid batteries store electricity through the bonding of battery acid and lead plates. Water must be added regularly to maintain the liquid level in the battery. Historically used in cars, these batteries require regular monitoring and maintenance to ensure proper performance.
For over fifty years, AGVs have been an important addition to the movement of materials and the improvement of production methods. Their ability to save time and increase efficiency has made them one of the most popular innovations in modern warehousing and production. In the last few years, as robotic technology has advanced, AGVs have had their abilities enhanced with the development of the AMR, autonomous mobile robot.
The primary distinction between AGVs and AMRs lies in the speed, intelligence, and efficiency of AMRs. AGVs follow a predetermined, guided route and are limited to executing basic instructions. They cannot adapt to obstacles in their path and require extensive programming to alter their applications or expand their functionality. In contrast, AMRs are designed to be faster and more adaptable, with advanced capabilities that allow them to navigate around obstacles and handle a broader range of tasks with greater efficiency.
An AMR has an onboard computer with sensors to evaluate its operating environment. They can navigate a complicated set of restrictions using an uploaded map that allows them to select the most efficient route to their destination. They can react to people, vehicles, and unplanned obstructions while successfully and safely completing their job. The chaos and confusion of the surrounding environment does not interfere with the completion of their tasks.
AMRs do not need adjustments to their work environment beyond incorporating a map into their programming. There is no requirement for laser sensors, guiding tape, or specialized pathways. Instead of altering the working conditions to accommodate the AMR, it adapts to fit various situations and can be easily reconfigured. These features generally make AMRs more cost-effective compared to AGVs.
A properly programmed AMR can quickly and efficiently complete an assembly process, make tooling changes, and finish complex tasks more precisely than humanly possible. Using robotic technology has the advantage of freeing people from dangerous and hazardous tasks since an AMR can enter any environment without a concern for its health or safety.
When selecting an AGV system, a key consideration is the type of computerized navigation it employs. Different industries and users have specific requirements for implementing AGVs, which in turn influences the choice of navigation system. Generally, the guidance system dictates the route and functions of the AGV. The performance of the AGV is heavily dependent on the quality of this system and its installation.
There are a wide variety of guidance systems that manufacturers use for AGV vehicles. They vary depending on whether they are fixed path or free ranging and include laser guided navigation (LGV), magnetic navigation, LiDAR NAVIGATION, magnetic spot navigation, wired navigation, optical navigation, or vision navigation. Each of the different types has benefits and are designed for specific purposes. Below is a short description of each. A more technical description can be found at the individual manufacturers‘ websites.
The LGV system uses a laser positioning device mounted on the top of the vehicle. Targets, located in its workspace, guide it. The navigation system sends laser signals to the targets, which sends signals back to the AGV navigation device. Three targets are required for the AGV to find its position. Corrections are made every 30 to 40 seconds. By industry standards, LGV‘s are incredibly accurate and easy to install.
Magnetic tape AGVs are equipped with magnetic sensors and follow a clearly defined path that is marked by magnetic tape. The tape induction system can be modified to account for line changes. The sensor measures the distance from the center of the tape and sends the information to the controller to adjust steering and path so that the AGV is always centered on the tape.
LiDAR navigation is also referred to as natural navigation. This system maps the environment with an assortment of sensors such as cameras, lidar, and lasers that are used for safety purposes. All of the data is combined with an internal inertial measurement unit (IMU) to help the AGV define and calculate its position. The array of calculations are made by a complex algorithm called SLAM (simultaneous localization and mapping).
For magnetic spot navigation, magnets are embedded in the floor for the AGV to follow at approximately 15 feet apart. The AGV moves from one spot to the next using sensors and controls such as half effect sensors, encoders, counters, gyros, and other such encoders to steer and guide the vehicle. A CAD drawing of the workspace is loaded in the system to serve as a reference. As with magnetic tape, installation is easy and quick.
When Mr. Barrett invented the first AGV, he initially used a wire suspended from the ceiling to guide the tug. Over time, he adapted the design by embedding the wire in the floor. Despite technological advancements, some manufacturers still use this original wire-based system. This involves burying a wire guide about one inch below the floor surface, which transmits signals to the AGV to regulate its steering and location.
Paint or colored tape is placed on the floor of the workspace. A built in sensor detects the path. There are systems that use ultraviolet light to light up the paint or tape. Highly sensitive cameras are able to recognize the AGVs path and position.
Vision activated systems use cameras that record the main features of the AGVs programmed route. Using vision sensors, the AGV system gets image information regarding its workspace. The system requires a camera, light, and hood to measure the ground texture. When navigating its workspace, the onboard system compares the recorded ground to its map to determine its position. The system is very accurate and has low hardware costs.
Automatic guided carts are a flexible and a less expensive alternative to an AGV system. Since they are smaller and more maneuverable, they have more versatility and can be easily adjusted. Their capacity varies depending on the manufacturer and model. Most can carry up to 2000 lbs. and tow loads heavier than they can carry. As with AGV‘s, each type has a different form of navigation.
Carts are an excellent alternative to conveyors or forklifts since they are cleaner, quieter, and easier to modify. They provide a fast and safe stream of products to and from selected areas and can be modified for non-production jobs such as warehouse organization.
The immediate advantage of a cart system is its cost-effectiveness compared to labor expenses. Materials flow smoothly and are readily accessible for operators. Upgrading a production environment with a cart system takes only a few hours, and additional carts can be easily integrated into the existing setup. The number of carts can be adjusted according to production needs. By removing the human factor from material handling, the installation of a cart system significantly reduces accidents and potential hazards.
Manufacturers have found that by using automation, they can significantly reduce errors and costs while raising quality and improving machine performance. Implementation of computer driven mechanisms increases production and efficiency approaching the point of perfection. Jobs that seemed to be impossible can be completed with ease in little time.
Initially, investing in an AGV system can be expensive requiring significant adjustments to manufacturing operations as well as the cost of the equipment. Once the system is in full operation, there is a noticeable reduction in labor costs with an increase in efficiency to balance the costs of implementation. Related additional savings can be seen in the reduction of labor.
Production environments have unsafe and hazardous conditions that include dangerous materials and substances. AGVs are perfect for those circumstances, which may endanger workers. The aircraft industry has huge engine components and parts that workers are unable to lift and can be lethal if they fall. AGVs are used to avoid damage to the materials and keep workers safe. In some cases, AGVs are equipped with robotic limbs to perform functions that require superior dexterity and strength, such as tooling changes.
The decision of what AGV system is best for your operation should be based on the needs of your facility. Every industry has their unique and specialized conditions. A close examination of each step of a process assists in determining where to place an AGV unit. As with all business decisions, the cost of a system can be a primary determining factor. AGV manufacturers have data that provides guidance to help in making a purchase choice. They are more than happy to assist with implementation and offer details on their system works.
The American National Standards Institute (ANSI) has endorsed the standards proposed by the Material Handling Industry of America (MHIA) for Automatic Guided Vehicle Systems (AGVS). These standards outline safety requirements for system suppliers, manufacturers, users, construction, application, operation, and maintenance of AGVS.
In 2012, MHIA established comprehensive safety standards for driverless and automatic industrial vehicles. These standards address all aspects of AGV equipment, including bumpers and required emergency controls. They also provide guidelines for converting manned vehicles to unmanned operation.
To be able to market an AGV vehicle, a manufacturer should be certified by the MHIA in several categories. The first category is a set of general requirements for AGV and other industrial equipment. The other categories are more specific to AGVs such as the type of permitted wireless components and includes a section on types of permitted batteries, chargers, motors, and other electrical components.
When making the choice to purchase an AGV system, it is wise to research manufacturers regarding their compliance with the MHIA regulations. In many ways, it is a protective umbrella to help avoid a bad investment.
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An autonomous mobile robot (AMR) is a self-propelled self-powered mechanism designed to perform repetitive tasks or organizational functions using an internal guidance system. They are able to navigate their...
Palletizing is the process of putting items on a pallet. The process of emptying the loaded objects in the reverse pattern is known as depalletizing. A pallet is a flat, square-shaped platform used to transport and...
A pallet stacker is a machine designed to assist the user in lifting, moving and handling palletized materials with ease. A pallet itself is a flat and horizontal structure used to support goods in a sturdy fashion...
A palletizer is an automated material handling machine used to stack and orient several individual products into a single load for a more convenient and economical method of handling, storage, and shipment. Palletizers are usually part of a bigger packaging process...
A robotic palletizer is a type of palletizer that employs a robotic arm to pick, orient, and place individual products and arrange them into a single stack of load. They are the next generation of palletizers, and they will supersede conventional palletizers...